Sound Source Separation and Music Content Analysis Demonstrations

Separation of Sound Sources

A fundamental problem in sound separation is that when two or more sounds
overlap with each other in time and frequency, separation is diffucult
and there is no general method to resolve the component sounds.
By making some assumptions of the underlying signals, the parameters of
the sources can be estimated from the mixture signals, and signals which
are perceptually close to the original ones can be synthesized.

Spectrum Modeling - Spectrum modeling with sinusoids plus noise

Sinusoidal modeling represents the periodic part of a signal
as a sum of sinusoids with time-varying amplitudes and frequencies.
The residual, which is ideally contains the non-periodic stochastic part of the signal,
is represented with filtered noise which
preserves the short-time energies within each Bark band.

Sinusoidal modeling
is a good mid-level reprentation and a powerful musical tool, because
it preserves the exact frequencies of harmonic partials. The parametric data
obtained from sinusoidal or stochastical modeling can be further utilized
for example in automatic transcription and instrument recognition. The estimated parameters can also be used to modify the pitch and speed of the signal (demonstrations)